| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| /** |
| * Normalization of text before the tokenizer. |
| * <p> |
| * CharFilters are chainable filters that normalize text before tokenization |
| * and provide mappings between normalized text offsets and the corresponding |
| * offset in the original text. |
| * </p> |
| * <H2>CharFilter offset mappings</H2> |
| * <p> |
| * CharFilters modify an input stream via a series of substring |
| * replacements (including deletions and insertions) to produce an output |
| * stream. There are three possible replacement cases: the replacement |
| * string has the same length as the original substring; the replacement |
| * is shorter; and the replacement is longer. In the latter two cases |
| * (when the replacement has a different length than the original), |
| * one or more offset correction mappings are required. |
| * </p> |
| * <p> |
| * When the replacement is shorter than the original (e.g. when the |
| * replacement is the empty string), a single offset correction mapping |
| * should be added at the replacement's end offset in the output stream. |
| * The <code>cumulativeDiff</code> parameter to the |
| * <code>addOffCorrectMapping()</code> method will be the sum of all |
| * previous replacement offset adjustments, with the addition of the |
| * difference between the lengths of the original substring and the |
| * replacement string (a positive value). |
| * </p> |
| * <p> |
| * When the replacement is longer than the original (e.g. when the |
| * original is the empty string), you should add as many offset |
| * correction mappings as the difference between the lengths of the |
| * replacement string and the original substring, starting at the |
| * end offset the original substring would have had in the output stream. |
| * The <code>cumulativeDiff</code> parameter to the |
| * <code>addOffCorrectMapping()</code> method will be the sum of all |
| * previous replacement offset adjustments, with the addition of the |
| * difference between the lengths of the original substring and the |
| * replacement string so far (a negative value). |
| * </p> |
| */ |
| package org.apache.lucene.analysis.charfilter; |
